[Osteoarticular protection of Zea mays L. purple variety (purple corn) in experimental arthritis in rats].

OBJECTIVES.: To evaluate the protective effect of Zea mays L., purple variety (purple corn) against inflammatory response and osteoarticular damage in rats with experimental arthritis.

MATERIALS AND METHODS.: Sixty-five Holtzman rats were used, assigned to seven groups: G1 (n=5): control; G2 (n=10): pristane (PIA) + distilled water; G3 (n=10): PIA + methotrexate 0.1 mg/kg; G4 (n=10): PIA + indomethacin 0.6 mg/kg; G5 (n=10): PIA + Zea mays 100 mg/kg; G6 (n=10): PIA + Zea mays 1000 mg/kg, and G7 (n=10): PIA + methotrexate 0.1 mg/kg + Zea mays 1000 mg/kg. Treatments were administered by orogastric cannula daily for 21 days; pristane was administered subdermal only on day 1. Volume of hind leg was recorded with a digital plethysmometer. The radiological analysis of the legs was evaluated according to the modified Clark criteria.

RESULTS.: The percentage of inflammation at the end of the experiment was: (G1) 1.50 ± 0.5; (G2) 13.73 ± 8.4; (G3) 14.76 ± 8.8; (G4) 14.22 ± 9.0; (G5) 10.81 ± 9.1; (G6) 5.31 ± 1.4; (G7) 6.38 ± 0.5. The radiological scores of the affected areas were: (G1) 0.6; (G2) 3.5; (G3) 0.6; (G4) 1.7; (G5) 1.9; (G6) 1.4; (G7) 1.0. Only the groups Zea mays L. 1000 mg/kg and methotrexate + Zea mays L. 1000 mg/kg showed a significantly lower inflammatory response (p<0.05) and showed significantly lower joint scores in relation to PIA.

CONCLUSIONS.: Zea mays L. (purple corn) reduces the inflammatory process and radiological modifications of PIA-induced arthritis in rats in a dose-dependent manner.